The WordPress.com upgrade Custom Design is pretty awesome…but if you’re like me, either you can’t afford it or you don’t want to spend all that money. You won’t have it all, but you will get away with some of it.
So first, click on the Customize tab that will let you customize your blog. After that, you will get to see your blog with the customizing sidebar. Roll your cursor over that, and click on the words “Custom Design”. Click on the button “Try Now”. The customizing sidebar will now have the buttons Fonts, CSS, and you get more control over the colors. Click on the Colors button. You’ll have several palettes to choose from. Once you’re satisfied with the color palette, there will be a built-in series of background images. Right-click on the background image you want and save it to your computer.
Now, exit the Custom Design trial. Go to your dashboard–>Appearance–>Background–>upload the background image from your computer. Ta-daaa!